Roofing



Patented Aug. 23, 1938 UNITED STATES PATENT OFFICE to Bird & Son, Inc.,

East Walpole, Mass., a

corporation of Massachusetts No Drawing.

Application June 19, 1937,

Serial No. 149,249

4 Claims.

This invention relates to mineral-surfaced roofing and has particularly to do with improvements in asphalt composition shingles and roll roofing having a mineral-surfacing of oil-coated granules,

5 grit, crushed slate or the like, bonded by a layer of asphalt to an asphalt-saturated fibrous backing layer, usually of felt.

The principal objects of the invention are to provide mineral-surfaced roofing in which the granules treated with a hydro-carbon oil are firmly adherent by means of a layer of asphalt to the backing layer and in which said granules of the roofing present a uniform color effect despite handling during manufacture, storage and placing of the product in position on a roof. These and other objects and advantages will hereinafter more fully appear.

Hereiofore, in the manufacture, storage, and use of asphalt composition roofing surfaced with mineral particles which have been treated against blistering by coating with hydro-carbon oil, it has frequently happened that faults and defects have developed which detract from its appearance, marketability and life, for example, loss of the granules because of adherence to the bituminous coating on the back side of the fibrous layer of an overlying shingle in a pile, and loosening of the granules which on the roof readily wash off. This commonly happens during storage and handling, particularly as the result of shingles being piled so that the asphalt coating on the back of the felt of an overlying shingle is directly pressed against the granules of the underlying shingle, thus causing the asphalt to adhere to such granules, especially in warm weather, or the granules to stick to the back coating and to be withdrawn from the face of the sheet, and is, of course, non-uniform and materially detracts from the color and appearance of the roofing when used. Such loss of granules is greatly aggravated bythe use of hydrocarbon oil upon the granules prior to their application to the roofing, and used in order to secure a better bond thereto. The hydro-carbon oil, being a solvent for the asphalt in the roofing, tends to liquefy this asphalt and spread it over the granules, thus causing the granules to pick up and retain dirt or dust, detracting from the appearance of the mineral surfacing. The use of the hydro-carbon oil, therefore, to minimize blistering? or entrance of moisture tending to free the granules from the surface of the roofing, has the substantial disadvantage of increasing variations in the shade of roofing. Shingles made in accordance with the present invention, however, provide both the superior bond secured by the use of hydro-carbon oil and prevent any loss of granules due to the use thereof.

I am familiar with the fact that in an effort to minimize loss of granules by blistering", granules heretofore have been treated or coated with various water-insoluble and bituminous oil-insoluble transparent or semi-transparent coatings. This has been done inwan endeavor to preserve the natural original color of the granules against the deleterious action of oil, water and foreign materials under normal storage and exposure condi tions. Such treatment has commonly involved the application to granules of a permanent coating, colored or uncolored, placed upon the granules before they are embedded in the asphalt of the base, and the coatings upon the granules have included various resinous and cellulose base materials applied to the granules by means of a solvent so as to provide thereon a continuous, substantially permanent water and bituminous oil insoluble coating. 7

Such method of overcoming loss has, however, a very serious objection for the pre-applied coating or film covering the surface of the granules remains between the asphalt and the material of the granule itself so that, though there is provided a good initial bond between the asphalt coating and the granule, this bond deteriorates due to weathering so that a great many granules come off or blister and come off. In the practice of this invention, the hydro-carbon oil-treated granules embed an oil film in the asphalt coating which simply acts as a primer to insure a strong bond directly between the granules and the asphalt because it fluxes with the asphalt coating.

I am also familiar with the proposed use of dextrine and glue to prevent staining, but the result here sought is materially different, i. e., to prevent adhesion between oil-coated granules and the back asphalt coat, which is so greatly aggravated by hydro-carbon oil or wax-treated granules and the back coating as in the roofing of this invention.

Roofing made in accordance with the preferred practice of this invention involves an asphalt-saturated fibrous backing layer, usually of felt saturated to -200% by weight, which layer is coated on its sides with the layers of asphalt including a certain amount of fine mesh mineral filler (say 2050% of the weight of the asphaltfiller mixture) so as to provide a stiffening backing coating of asphalt, which, in addition, serves .to preserve the asphalt-saturant in the backing layer, and also provide a top coating or granulebonding layer of asphalt. The granules themselves, prior to their application to the bonding layer of asphalt upon the backing, are treated with 8 to 20 lbs. of 45 to seconds at 100 F. I

(Saybolt Universal) viscosity oil per ton of granules, followed by the application of such granules to the roofing in the ordinary manufacture of roofing material, and then applying to the roofing thus made a water-starch solution (say 10 lbs of starch to 100 lbs. of water) in the amount of 25 to 40 lbs. per ton of granules. This may be done by spraying or in any other suitable manner, and forms on the granules of the roofing material a hardenable, substantially colorless or translucent, though water-soluble, coating. Other materials adapted to form such a coating are dextrines, soap, gums, glues, gelatin and sugars, or, in fact, any material adapted to function as a coating as above described and at the same time be water-soluble so as to disappear and wash away under the influence of weathering when placed upon the roof. As a practical matter, starch is found to be washed away ordinarily in two months, and the color of the granules in the meantime maintained until the weathering slightly turns the color of the exposed granules. In this'way, the fugitive material is placed upon the granules immediately following the application of the granules to the roofing, and, despite the hydro-carbon oil coating on the granules, protects them throughout the subsequent handling, storage in piles, shipment and application upon the roof, and even serves to provide a uniform color throughout such period until weathering can get in its work. At the same time an excellent bond afforded by the hydro-carbon oil is secured without the blistering" which is characteristic of roofing made without the use of hydro-carbon oil.

Though the invention has been described with respect to roofing having but a single layer of asphalt and granules thereon, it is obvious that the invention is equally applicable to a roofing having additional overlying layers of asphalt and granules thereon so that a layer of granules is exposed on the surface.

What I claim as new, is:

1. In ornamental roofing of the class described, an asphalt-saturated felt base, a layer of asphalt on the back side of said base, a bonding layer of asphalt on the upper surface of said base, a uniform layer of exposed hydro-carbon oil-treated mineral granules directly attached to said bonding. layer of asphalt through the medium of an asphaltic bond fiuxed by a hydro.- carbon oil, and a hardened, substantially color? less, water-soluble fugitive coating upon the weather-exposed surfaces only of said granules.

2. In ornamental roofing of the class described, an asphalt-saturated felt base, a layer of asphalt on the back side of said base, a bonding layer of asphalt on the upper surface of said base, a uniform layer of exposed hydro-carbon oil-treated mineral granules attached to said layer of asphalt, and a hardened, substantially colorless, water-soluble fugitive starch coating upon the hydro-carbon oil-treated weather-exposed surfaces only of said granules.

3. The method of making composition roofing surfaced with granular mineral surfacing material which comprises applying hydro-carbon oiltreated granules to an asphalt-saturated base coated with asphalt so as to establish an asphaltic bond therewith, partially embedding the granules in said asphalt, and then applying 'to the weather-exposed surfaces of said granules a hardenable, substantially colorless, water-soluble coating whereby to provide a fugitive protective coating thereon.

4, The method of making composition roofing surfaced with granular mineral surfacing material which comprises applying hydro-carbon oilthe weather-exposed surfaces of said granules a hardenable, substantially colorless, water-soluble coating whereby to provide a fugitive starch coating thereon.

' FRANK P. REYNOLDS. 

